江苏省鸡肉产品中弯曲菌耐药特征及Ⅰ型整合子分析

Antimicrobial Resistance Characteristics and Epidemiology of Class Ⅰ Integron of Campylobacter Isolated from Chicken Meat in Jiangsu Province

为探讨鸡肉产品中弯曲菌的耐药特征,本研究以2016~2017年分离于江苏省市售鸡肉中弯曲菌分离株为研究对象,采用K-B纸片扩散法测定分离株对9大类21种抗生素的敏感性,同时应用PCR法检测Ⅰ型整合子的整合酶基因、3’-CS以及可变区耐药基因。研究显示:弯曲菌分离株对环丙沙星、头孢噻肟、氧氟沙星、卡那霉素、氨苄西林耐药率较高,分别为83.16%、80.0%、68.0%、65.0%和64.2%。47.3%(45/95)的菌株为Ⅰ型整合酶基因阳性,10株分离株具有3’-CS端,其中5株分离株为可变区阳性,其耐药基因盒为aad A1。结论:鸡肉产品中分离到的弯曲菌多重耐药现象严重,整合子介导的多重耐药在江苏地区并不是主导的耐药机制,但其携带的耐药基因可在不同细菌间传递从而通过食物链传递给人类,应严格监测鸡肉产品中弯曲菌的耐药特征及Ⅰ型整合子的流行情况。

Campylobacter isolated from chicken meat in Jiangsu province during 2016-2017 were used as the study subject to investigate the antimicrobial resistance characteristics of campylobacter in chicken meat. K-B method was used to examine for antimicrobial susceptibility to 21 antibiotics in 9 categories, the class Ⅰ integrase gene（int1） and 3＇-CS region, and the gene cassette of class Ⅰ integron were amplified by PCR. The results revealed that the resistance of campylobacter isolated strains to ciprofloxacin, cefotaxime, loxacin, kanamycin and ampicillin were 83.16%, 80.0%, 68.0%, 65.0% and 64.2%, respectively. Int1 was detected in 47.3%（45/95） of the Campylobacter isolates and 10 stains contained 3＇-CS region, of which 5 strains were positive for gene cassette detected by PCR. The sequencing analysis demonstrated that the add A1 gene cassette encoded resistance to streptomycin was identified. The results suggested that the multiple resistance of the Campylobacter isolated from chicken meat were serious. The mechanism of multidrug resistance mediated by integrons might not represent a significant mechanism for the dissemination of antimicrobial resistance determinants in Campylobacter in Jiangsu province. However, the drug resistance gene in class I integrons could be transmitted to human through different bacteria via the food-chains. The multiple resistance and prevalence of class I integrons in chicken meat should be concerned strictly.